Device-to-device content providing method

ABSTRACT

The present disclosure relates to a device-to-device (D2D) content providing method, and relates to a method for enabling D2D content transmission through a link with a communication control server for supporting D2D content transmission. To this end, the D2D content providing method can comprise the steps of: generating, by a terminal, an adjacent terminal list by searching for at least one connectable adjacent terminal; transmitting, to a communication control server, the adjacent terminal list and a D2D communication request for content including information on an available communication interface by the terminal; receiving, from the communication control server, information on one or more content providing terminals, which can provide the content selected on the basis of the information on the communication interface among adjacent terminals included in the adjacent terminal list, by the terminal; and making a request, to the content providing terminal, and receiving the content by the terminal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No.PCT/KR2015/008090, filed Aug. 3, 2015, which claims the priority to andthe benefit of Korean Patent Application No. 10-2014-0142568 filed inthe Korean Intellectual Property Office on Oct. 21, 2014. Thedisclosures of above-listed applications are hereby incorporated byreference in their entirely

TECHNICAL FIELD

The present disclosure relates to a device-to-device (D2D) contentproviding method, and relates to a method for enabling D2D contenttransmission through a link with a communication control server forsupporting D2D content transmission.

BACKGROUND

Details disclosed herein merely offer background information regardingembodiments and are not applicable as prior art.

With the development of communication devices and systems, users need aservice which allows the user to easily obtain or share desiredinformation at any time. With the recent advent of a smart phone and atablet PC, an environment for obtaining and sharing various kinds ofinformation through a communication system is already constructed.However, the inventor(s) has experienced that the communication systemhas a problem of failing to effectively provide real-time informationdue to system complexity or time delay.

Therefore, Device-to-Device (D2D) communication technology that performsdirect communication between devices is attracting attention.

The D2D communication refers to communication technology capable ofestablishing a direct communication link between devices andtransmitting data without using infrastructures such as a base stationwhen the devices are located within a close range from each other.

In this D2D communication, a device finds any other physicallyneighboring device, establishes a communication session, and transmitstraffic. Thus, this has an advantage of solving a traffic overload issueby dispersing traffic concentrated on a base station. Nonetheless, theD2D communication today has a problem in having to perform complicatedseveral procedures in which a device that supports a D2D communicationmodule searches for other neighboring devices, sends a query aboutdesired content to all the discovered devices, receives responses,identifies other device having the content, sends again a request forthe content to the identified device, and receives the content.

SUMMARY

In order to accomplish the above objects, a device-to-device (D2D)content providing method according to an embodiment of the presentdisclosure may comprise steps of: at a device, creating a neighboringdevice list by discovering at least one connectible neighboring device;at the device, transmitting a D2D communication request for content to acommunication control server, the request including the neighboringdevice list and information about an available communication interface;at the device, receiving, from the communication control server,information about one or more content providing devices selected fromamong neighboring devices contained in the neighboring device list,based on the information about the communication interface; and at thedevice, requesting and receiving content from the content providingdevice.

In order to accomplish the above objects, a device-to-device (D2D)content providing method according to an embodiment of the presentdisclosure may comprise steps of: at a communication control server forcontrolling D2D communication, receiving a D2D communication request forcontent from one device, the request including a neighboring devicelist; at the communication control server, identifying a device list ofother devices having the content requested by the device by interworkingwith a device management server for managing information about deviceshaving contents; at the communication control server, selecting one ormore content providing devices by checking the neighboring device listreceived from the device and the device list identified through thedevice management server; and at the communication control server, ifthe selected content providing devices exist more than two, extracting afinal content providing device by comparing information aboutcommunication interfaces available in the device with information aboutcommunication interfaces available in each of the content providingdevices and then transmitting information about the final contentproviding device to the device, or arranging the content providingdevices according to predetermined priorities of communicationinterfaces and then transmitting a list of the arranged contentproviding devices to the device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exemplary diagram illustrating main elements of a systemaccording to one or more embodiments.

FIG. 2 is an exemplary diagram illustrating a method for discovering aneighboring device according to one or more embodiments.

FIG. 3 is an exemplary block diagram illustrating main elements of adevice shown in FIG. 1 according to one or more embodiments.

FIG. 4 is an exemplary block diagram illustrating main elements of acommunication control server shown in FIG. 1 according one or moreembodiments.

FIG. 5 is an exemplary flow diagram illustrating a D2D content providingmethod performed at a device according to one or more embodiments.

FIG. 6 is an exemplary flow diagram illustrating a D2D content providingmethod according to one or more embodiments.

FIG. 7 is an exemplary flow diagram illustrating a D2D content providingmethod according to one or more embodiments.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be describedwith reference to the accompanying drawings. In the description ofembodiments of the present disclosure, well known functions or elementsmay not be described or illustrated in detail to avoid obscuring thesubject matter of the present disclosure. While the followingdescription is particularly shown and described with reference toexemplary embodiments thereof, the following description of exemplaryembodiments is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

Additionally, the terms including expressions “first”, “second”, etc.are used for merely distinguishing one element from other elements butdo not limit the corresponding elements. The above expressions do notlimit the sequence and/or importance of the elements.

Further, when it is stated that a certain element is “coupled to” or“connected to” another element, the element may be logically orphysically coupled to or connected to another element. Namely, theelement may be directly coupled or connected to another element, or anew element may exist between both elements.

Also, the terms used in describing various embodiments of the presentdisclosure are only examples for describing a specific embodiment but donot limit such embodiments. Singular forms are intended to includeplural forms unless the context clearly indicates otherwise. Unlessdefined differently, all terms used herein, which include technicalterminologies or scientific terminologies, have the same meaning as thatunderstood by a person skilled in the art to which the presentdisclosure belongs. The terms “include”, “comprise”, and “have” as wellas derivatives thereof, mean inclusion without limitation.

Now, a D2D content providing method according to embodiments of thepresent disclosure and a computer-readable storage medium recordingthereon a program for the method will be described in detail withreference to the drawings. Through the drawings, the same or similarreference numerals denote corresponding features consistently.

At the outset, the configuration of a system according to an embodimentof the present disclosure will be described.

FIG. 1 is an exemplary diagram illustrating main elements of a systemaccording to one or more embodiments.

Referring to FIG. 1 , the system according to one or more embodiments ofthe present disclosure supports content transmission between a pluralityof devices 100 a, 100 b and 100 c (hereinafter, denoted by 100 if noseparate distinction is required) and, especially, supportscommunication between the devices 100 through interworking with acommunication control server 400 that controls D2D communication andwith a device management server 500 that manages a list of devices.

Describing each element, the plurality of devices 100 refers to userdevices capable of transmitting or receiving various kinds of datadepending on users' manipulations. Particularly, the device 100according to one or more embodiments of the present disclosure maysupport direct transmission/reception of content between devices in adevice-to-device (D2D) communication manner without passing through acommunication network 300. Namely, the device 100 according to one ormore embodiments of the present disclosure may create a neighboringdevice list by discovering one or more connectible neighboring devicesand then transmit the list to the communication control server 400.Also, the device 100 may receive information about a specific contentproviding device specified by the communication control server 400 fromamong neighboring devices contained in the neighboring device list andthen request and receive content from the specific content providingdevice.

In a normal D2D communication scheme, the device 100 discoversneighboring devices, identifies a device having desired content bysending a request for a content possession list to neighboring devicesor querying whether there is the desired content and receivingresponses, and then requests and receives the desired content from theidentified device. In contrast, according to one or more embodiments ofthe present disclosure, when the device 100 provides information aboutneighboring devices to the communication control server 400, thecommunication control server 400 selects an optimal content providingdevice from among neighboring devices as to the device 100 and offersrelated information to the device 100. Then the device 100 requests andreceives content from the optimal content providing device. This isdifferent from a normal D2D communication scheme.

Additionally, the device 100 of the present disclosure may requestspecific content of the content providing device and receive a completeform of a content file from the content providing device. In this case,if there are two or more content providing devices, and if such contentproviding devices store lots of fragments of a content file in adistributed manner, the device 100 may receive such fragments of thecontent file in parallel from the content providing devices and thencombine them into a single content file. Also, the device 100 mayoperate as a content providing device with regard to other devices.

Further, the device 100 of the present disclosure may transmit orreceive information to or from the communication control server 400 orthe device management server 500 via the communication network 300. Forthis, the device 100 of the present disclosure may include a browser fortransmission and reception of information, a memory for storing programsand protocols, a microprocessor for executing, operating and controllingvarious kinds of programs, and the like.

The communication control server 400 performs a function of controllingtransmission of content between the devices 100. In particular, thecommunication control server 400 according to one or more embodiments ofthe present disclosure registers and manages information about thedevices 100 which participate in D2D communication. Also, when a requestfor D2D communication regarding specific content, including aneighboring device list, is received from a specific device 100, thecommunication control server 400 may select a device having the contentrequested by the device 100 from among neighboring devices contained inthe neighboring device list, and then offer this information about acontent providing device to the device 100.

Additionally, if there are two or more devices having the contentrequested by the device 100, the communication control server 400 mayselect a content providing device in accordance with a particular ruleand then offer selection information to the device 100.

The device management server 500 is an element for managing informationabout a plurality of devices 100 which participate in D2D communication.The device management server 500 of the present disclosure may receive,from the communication control server 400, information about contentrequested by the device 100, and manage it as information about contentpossessed by the device 100. Also, the device management server 500 mayreceive, from the communication control server 400, a content possessionlist offered by the device 100 and manage it as information aboutcontent possessed by the device 100.

Such devices 100 that participate in D2D communication refer to a devicewhich stores all or part of specific content and is capable ofrequesting and receiving content from other device or providing contentat the request of other device. These devices 100 may be classified intoa seeder storing the whole content for sharing and a leecher storingsome segments smaller than the original size of content for sharing. Inaddition, the seeder may include a device downloading the whole contentfor sharing from other device as well as a device initially providingcontent for sharing. The device management server 500 stores and managesinformation about such possessed contents with regard to the devices 100that participate in D2D communication.

Although the communication control server 400 and the device managementserver 500 of the present disclosure are shown as a separate form in thedrawing, this is exemplary only. The communication control server 400and the device management server 500 may exist as a single form of adevice optimization server 600, or the communication control server 400may perform the function of the device management server 500.

Details about main elements and operation methods of the device 100 andthe communication control server 400 will be described below. Aprocessor equipped in the device 100 and in the communication controlserver 400 according to one or more embodiments of the presentdisclosure may process program instructions for performing the methodaccording to the present disclosure. This processor may be asingle-threaded processor in one embodiment and a multi-threadedprocessor in another embodiment. Further, this processor may processcommands stored in a memory or storage.

The system according to one or more embodiments of the presentdisclosure may be configured to further include a content providingapparatus (not shown). The content providing apparatus (not shown)performs a function of providing content to the device 100. If there isno neighboring device as to the first device 100 a that requestscontent, or if there is no neighboring device having content requestedby the first device 100 a, the first device 100 a may request andreceive the content from the content providing apparatus (not shown)under the control of the communication control server 400.

Additionally, the devices 100, the communication control server 400 andthe device management server 500 according to one or more embodiments ofthe present disclosure may transmit or receive information through thecommunication network 300.

The communication network 300 may use various forms of communicationnetworks, for example, wireless communication schemes, such as WLAN(Wireless LAN), Wi-Fi, Wibro, Wimax, and HSDPA (High Speed DownlinkPacket Access), or wired communication schemes, such as Ethernet, xDSL(ADSL, VDSL), HFC (Hybrid Fiber Coaxial cable), FTTC (Fiber to theCurb), and FTTH (Fiber to the Home). In addition to the abovecommunication schemes, any other communication scheme which is wellknown or to be developed may be used.

Also, the communication network 300 may include a plurality of accessnetworks 320 a, 320 b and 320 c (hereinafter, denoted by 320 if noseparate distinction is required) for supporting communication access ofthe device 100, and a core network 310. The core network 310 of thepresent disclosure supports a connection between the access networks 320and may support a connection between the one or more access networks 320and any other communication network. The core network 310 of the presentdisclosure may be implemented as an IP network, for example.

The access networks 320 may have different communication coverage andtransmit or receive information to or from to the device 100 located inthe corresponding communication coverage. The access network 320 may beconnected to the device 100, based on various communication schemes,e.g., mobile communication such as Wi-Fi communication, LTE, and 3G,Bluetooth communication, and the like. Also, the access network 320 maybe implemented to include one or more base station apparatuses which notonly detect the device 100 approaching the communication coverage, butalso perform an access control and radio resource allocation for theaccess-requesting device 100, information transmission/reception of thedevice 100 through the allocated radio resource, and the like. The basestation apparatus may be, for example, eNB (e Node B) in the LTEstandard, and Wi-Fi AP (Access Point).

The device 100 according to one or more embodiments of the presentdisclosure may be connected with the access network 320 of variousschemes. For example, the first device 100 a may be connected with onlythe first access network 100 a of Wi-Fi communication scheme. On theother hand, the second device 100 b may be connected with both the firstaccess network 100 a of Wi-Fi communication scheme and the second accessnetwork 100 b of LTE communication scheme. Also, the third device 100 cmay be connected with the third access network 100 c of 3G communicationscheme as well. In this case, for using a specific service, the device100 that supports various communication schemes may be connected withthe core network 310 through the access network 320 that supports one ofcommunication schemes.

Additionally, the device 100 according to one or more embodiments of thepresent disclosure may be configured to include an interface module fora connection with the access network 320 and also include an interfacemodule for supporting a D2D communication function. When the interfacemodule that supports the D2D communication function is activated, thedevice 100 may discover one or more connectible neighboring devices andcreate a neighboring device list.

This will be described with reference to FIG. 2 .

FIG. 2 is an exemplary diagram illustrating a method for discovering aneighboring device according to one or more embodiments.

The core network 310 forming the communication network 300 of thedisclosure may be configured to include a serving gateway (hereinafterreferred to as SGW) 311, a packet data network gateway (hereinafterreferred to as PGW) 312, and a mobility management entity (MME, notshown).

The SGW 311 is an end point of the core network 310 and the accessnetwork 320 and performs an anchoring function for the movement of thedevice 100 between the access networks 320. For example, in the LTEnetwork, the SGW 311 may perform the function of a mobility anchor atthe handover of the device 100 and the function of a mobility anchor ata movement in the 3GPP radio network. The core network 310 includes oneor more SGWs 311, and each SGW 311 may be connected with one or morebase station apparatuses of the access network 310 through a convergedswitch or the like.

The PGW 312 is a point of contact with other communication networks suchas IP multimedia subsystem (IMS), Internet, or a mobile communicationnetwork of other communication provider, and is responsible foranchoring as to the movement of the device 100 between communicationnetworks. Specifically, the PGW 312 may assign an internet protocol (IP)address to the device 100. Also, the PGW 312 may perform the function ofa mobility anchor in case of a movement between different type networks(e.g., 3GPP wireless network and non-3GPP wireless network). Inaddition, the PGW 312 determines a bearer band to be provided to thedevice 100. Also, the PGW 312 performs forwarding and routing functionsfor packet. And also, the PGW 312 may perform a QoS policy application,a traffic control, and a charging process for each device 100 byinterworking with a policy and charging rules function (PCRF) (notshown). This PGW 312 is connected with one or more SGWs 311 as lowernodes. For reference, the communication control server 400 and thedevice management server 500 according to the present disclosure may beconnected with the SGW 311. If the communication control server 400 andthe device management server 500 exist in a single form, the deviceoptimization server 600 may also be connected with the SGW 311.

The access network 320 forming the communication network 300 of thepresent disclosure may be implemented as one or more base stationapparatuses that transmit or receive data. This base station apparatusmay be composed of a radio unit (RU) for processing radio signals and adigital unit (DU) for converting radio signals into digital data andperforming data processing in accordance with a communication protocol.The RU may be referred to as a remote radio head (RRH), and the DU maybe referred to as a base band unit (BBH).

The RU and the DU may be implemented in a united form at the same placeor separately constructed at remote places while connected through anoptical cable or a cable. Recently, the latter structure which isadvantageous relatively in view of network construction cost andoperation convenience is widely used.

FIG. 2 shows the access network based on the latter structure. Referringto FIGS. 1 and 2 , the access network 320 may be configured to includethe RUs 320 a˜320 i that are installed in respective cells, which dividefrom a service target area in the unit of communication coverage, andperform radio access and data transmission/reception with the devices100 a˜100 i located in the communication coverage of correspondingcells, and the one or more DUs 322 a˜322 c that are connected with theRUs 320 a˜320 i and perform processing of radio data transmitted to orreceived from the RUs 320 a˜320 i.

Based on this structure of the communication network 300, the devices100 a˜100 i may perform a process of discovering neighboring devicesthrough interworking with the RUs 321 a˜321 i and the DUs 322 a˜322 c.At this time, in order to discover neighboring devices, the device 100identifies location information of neighboring devices throughinterworking with the RUs 321 a˜321 i and the DUs 322 a˜322 c. Herein,the location information may include cell identification information(Cell ID) for distinguishing cells each of which is communicationcoverage of each RU 321 a˜321 i, DU identification information (DU ID)for identifying the one or more DUs 322 a˜322 c each of which isconnected with the one or more RUs 321 a˜321 i, and IP information ofthe device 100. Further, the location information may include one ormore of SGW identification information (SGW ID) for identifying the SGW311 connected with the DUs 322 a˜322 c, PDN gateway identificationinformation (PGW ID) for identifying the PGW 312 connected with the oneor more SGW 311, communication network operator information, andnational information.

The device 100 may receive such information from the MME (not shown) ofthe core network 322 with which the DUs 322 a˜322 c interwork, orrequest and receive such information from the MME (not shown) of thecore network 322 via the DUs 322 a˜322 c.

Each of the devices 100 a˜100 i may create a neighboring device list byusing the identified information. For example, the first device 100 amay identify the location information about the second, third, fourthand fifth devices 100 b, 100 c, 100 d and 100 e located nearby within acertain range through the accessed first RU 321 a and the first DU 322 aconnected with the first RU 321 a. Also, the first device 100 a maycreate a neighboring device list that contains IP address information ofthe second, third, fourth and fifth devices 100 b, 100 c, 100 d and 100e.

Additionally, the device 100 according to one or more embodiments of thepresent disclosure may obtain identification information (IP addressinformation) about at least one other device through a D2D discoverymessage transmitted and received within a specific range, or obtainidentification information, i.e., IP address information, about at leastone other device by emitting a D2D discovery message within a specificrange and receiving a response message. Namely, the first device 100 amay obtain identification information about the second and fourthdevices 100 b and 100 d by using D2D discovery messages transmitted toand received from the second and fourth devices 100 b and 100 d whichare located within a specific range. Also, the first device 100 a maybroadcast D2D discovery messages within a specific range and then, ifresponse messages are received from the second and fourth devices 100 band 100 d, create a neighboring device list by defining the second andfourth devices 100 b and 100 d as neighboring devices.

Additionally, the devices 100 a˜100 i according to one or moreembodiments of the present disclosure may establish priorities of thediscovered other devices by using the identified location information,and preferentially select a specific other device having a higherpriority as a neighboring device. Such priorities may be established inthe order of Cell ID, DU ID, SGW ID, PGW ID, communication networkoperator information, and national information. According to this,neighboring devices may be selected in the order of devices located inthe same cell, the same DU, the same serving gateway, the same PDNgateway, the same operator network, and the same nation.

Additionally, when creating a neighboring device list, the device 100a˜100 i according to one or more embodiments of the present disclosuremay calculate a content transmission quality factor between deviceshaving the identified location information, select a device only havingthe calculated content transmission quality factor greater than a givenvalue, and then create the neighboring device list. The contenttransmission quality factor may be calculated using received signalstrength or signal to noise ratio (SNR) between devices.

Hereinafter, main elements and an operation method of the device 100according to one or more embodiments of the present disclosure will bedescribed.

FIG. 3 is an exemplary block diagram illustrating main elements of adevice shown in FIG. 1 according to one or more embodiments.

Referring to FIGS. 1 and 3 , the device 100 according to one or moreembodiments of the present disclosure may be configured to include acommunication unit 110, an input unit 120, a control unit 130, a memoryunit 140, and a display unit 150.

Respective elements will be described in detail. The communication unit110 performs a function of supporting transmission and reception ofvarious kinds of information. Particularly, the communication unit 110according to one or more embodiments of the present disclosure may beconfigured to include a first interface 111 for supporting D2Dcommunication and a second interface 112 for supporting access to thecommunication network 300. On the one hand, the first interface 111 maybe activated under the control of the control unit 130 and then performa process of discovering neighboring devices. On the other hand, thesecond interface 112 may perform a process of accessing the accessnetwork 320 of the communication network 300 under the control of thecontrol unit 130.

The access network 320 of the present disclosure may support variouscommunication schemes, and thus the second interface 112 may beconfigured to include at least one of a Wi-Fi module, an LTEcommunication module, a 3G communication module, and a Bluetoothcommunication module.

Additionally, the second interface 112 may support a process ofaccessing the access network 320 by activating various communicationmodules in accordance with user's setting or a predefined manner. Forexample, if the Wi-Fi communication performance is lower than predefinedcommunication performance in a state of accessing through the Wi-Fimodule the access network 320 that supports the Wi-Fi communicationscheme, the second interface 112 may trigger the LTE communicationmodule and support the whole process of transferring to the accessnetwork 320 that supports the LTE communication scheme.

Also, under the control of the control unit 130, the second interface112 of the present disclosure may transmit a D2D communication requestto the communication control server 400 or the device management server500 via the communication network 300. Then the second interface 112 mayreceive a corresponding response from the communication control server400 or the terminal management server 500.

The input unit 120 delivers, to the control unit 130, various kinds ofinformation entered by a user and a signal entered in connection withsetting or controlling various functions of the device 100.Particularly, the input unit 120 of the present disclosure may activatethe first interface 111 or support a user's input of a uniform resourcelocator (URL) for a content request.

The input unit 120 may include a key input tool such as a keyboard or akeypad, a touch input tool such as a touch sensor or a touch pad, avoice input tool, and a gesture input tool having at least one of a gyrosensor, a geomagnetic sensor, an acceleration sensor, a proximitysensor, and a camera. Besides, all kinds of input tools being developedor to be developed may be included.

The control unit 130 performs the overall control of the device 100. Inview of hardware, the control unit 130 may be configured to include atleast one processor such as a central processing unit (CPU) and a microprocessing unit (MPU), at least one execution memory (e.g., a registerand/or a random access memory (RAM)) onto which data is loaded, and abus for inputting or outputting data to or from the processor and thememory. In view of software, the control unit 130 may be configured toinclude a program routine or program data loaded onto the executionmemory from a recording medium and then processed by the processor so asto perform a function defined in the device 100. Namely, any processableelement in view of software among functions possessed by the device 100so as to support the D2D content providing method according to one ormore embodiments of the present disclosure may be considered as afunction of the control unit 130.

The control unit 130 of the present disclosure is functionally connectedwith one or more elements equipped to support the D2D content providingmethod according to one or more embodiments of the present disclosure.Namely, the control unit 130 is functionally connected with thecommunication unit 110, the input unit 120, the memory unit 140, and thedisplay unit 150, and controls the supply of power to each element andthe flow of signals for performing functions.

In particular, the control unit 130 according to one or more embodimentsof the present disclosure may perform a process of discoveringneighboring devices and creating a neighboring device list of thediscovered neighboring devices. Herein, the neighboring device list maybe created by the control unit 130 when a specific site or applicationis executed for using a service and then a request for specific contentoccurs or when the first interface 111 of the communication unit 110 isactivated.

In order to create the neighboring device list, the control unit 130 ofthe present disclosure may obtain identification information about atleast one other device through a D2D discovery message transmitted andreceived within a specific range, obtain identification informationabout at least one other device by emitting a D2D discovery messagewithin a specific range and receiving a corresponding response message,or obtain identification information about at least one other devicethrough interworking with the DU connected with one or more RUs locatedin the access network accessed by the device. Then the control unit 130may create the neighboring device list by defining the obtainedidentification information about other device as a neighboring device.The neighboring device list of the present disclosure may contain, asidentification information, IP address information about a neighboringdevice.

The control unit 130 according to one or more embodiments of the presentdisclosure may create the neighboring device list by selecting, fromamong the discovered devices, only the device having a contenttransmission quality factor greater than a given value. For this, thecontrol unit 130 of the present disclosure may transmit a signal forcalculation of a content transmission quality factor to the discoveredother device and then calculate the content transmission quality factorby computing a transmission rate, etc., based on a response. Namely, thecontrol unit 130 may calculate the content transmission quality factorby using received signal strength, SNR, or the like. Also, the controlunit 130 of the present disclosure may query the discovered other deviceabout whether there is any other device connected thereto. If a responseindicates that several devices are connected to the discovered otherdevice, this device may be excluded from the selection of neighboringdevices. Namely, the control unit 130 may preferentially select, as theneighboring device, a certain device having no or less connection withother device.

Additionally, when the neighboring device list is created, the controlunit 130 may transmit a D2D communication request to the communicationcontrol server 400 together with information about content to be used.At this time, the control unit 130 of the present disclosure may alsotransmit information about any available communication interface to thecommunication control server 400.

Additionally, the control unit 130 of the present disclosure may alsotransmit a content possession list, which is a list of one or morepossessed contents, to the communication control server 400. The contentpossession list may be utilized as information required for the device100 to operate as a content providing device as to other device underthe control of the communication control server 400.

Additionally, the control unit 130 may receive information about acontent providing device selected, from among neighboring devicescontained in the neighboring device list, by the communication controlserver 400 capable of providing content. When the information about thecontent providing device is received, the control unit 130 may requestand receive content from the corresponding content providing device. Atthis time, since identification information (IP address) of the contentproviding device is already contained in the neighboring device list,the control unit 130 may immediately request and receive the contentfrom the content providing device without any process of discovering thecontent providing device.

On the other hand, if there is no neighboring device as the result ofdiscovery, the control unit 130 may transmit, to the communicationcontrol server 400, a D2D communication request for specific content byincluding only information about an available communication interface,and receive, from the communication control server 400, responseinformation about a content providing device which is not neighboringbut has the content. Also, the control unit 130 may receive addressinformation about a content server (not shown) having the content fromthe communication control server 400. Thereafter, using the receivedinformation, the control unit 130 may request and receive the contentfrom the content providing device or the content server (not shown).

The control unit 130 that receives the content through the above processmay store temporarily or permanently the received content in the memoryunit 140. Also, the control unit 130 may control a process oftransmitting the temporarily or permanently stored content to otherdevice in response to a request of the other device. That is, in the D2Dcommunication manner, the device 100 of the present disclosure mayreceive content from any other device and provide content to any otherdevice.

In order to perform the above-discussed process, the control unit 130according to one or more embodiments of the present disclosure may beconfigured to include a device discovery module 131, a list creationmodule 132, and a content control module 133.

Also, as identification information about the device of the presentdisclosure, any information for distinguishing between devices 100, inaddition to IP address information, such as an international mobileequipment identity (IMEI), a personal identification number (PIN), anIMSI, a unique universal identifier (UUID), a UDID, a mobileidentification number (MIN), a mobile subscription identification number(MSIN), a mobile directory number (MDN), and a mobile stationinternational ISDN number (MSISDN).

The memory unit 140 may temporarily store application programs requiredfor the operation of functions according to one or more embodiments ofthe present disclosure and various data created during the execution ofthe application programs. Particularly, the memory unit 140 according toone or more embodiments of the present disclosure may store content 141.Further, the memory unit 140 may store a neighboring device list 142created by the control unit 130. Information stored in the memory unit140 may be maintained temporarily or permanently.

The memory unit 140 may include mainly a program region and a dataregion. The program region stores related information for the operationof the device 100, such as an operating system (OS) for booting thedevice 100. The data region stores data created by the use of the device100, and may store the content 141 and the neighboring device list 142as mentioned above. The memory unit 140 may be formed of storage mediasuch a flash memory, a hard disk, a multimedia card micro type memory(e.g., SD or XD memory, etc.), RAM, and ROM.

The display unit 150 displays information about an operating status andan operating result produced during the execution of functions of thedevice 100. Particularly, the display unit 150 of the present disclosuremay display various kinds of information associated with the use ofcontent.

The display unit 150 of the present disclosure may be implemented in theform of a single touch panel (or touch screen) together with the inputunit 120. In this case, the display unit 150 may display various kindsof information produced according to user's touch action.

Additionally, the display unit 150 may be formed of a liquid crystaldisplay (LCD), a thin film transistor LCD (TFT-LCD), an organic lightemitting diodes (OLED), an LED, an active matrix organic LED (AMOLED), aflexible display, a 3-dimensional display, or the like. Some of them mayhave a transparent or light-penetrate form through which the outside canbe seen. This may be configured in the form of a transparent displayincluding a transparent OLED (TOLED).

Hereinbefore, main elements of the device 100 are described through FIG.3 . The elements shown in FIG. 3 are, however, not always essential, andmore or less elements than shown may be used for the device 100. Forexample, the device 100 may further include an audio output unit (notshown) for converting an electric audio signal into an analog signal andthen outputting the signal. This audio output unit (not shown) mayperform a function of supporting the output of various kinds ofinformation associated with content.

Additionally, the main elements of the devices 100 shown in FIG. 3 maybe varied in position for convenience or any other reason. Although onlythe device discovery module 131, the list creation module 132, and thecontent control module 133 are shown as modules for constituting thecontrol unit 130, the present disclosure is not limited to that. Thecontrol unit 130 may be formed of various modules for performing variousfunctions.

Hereinbefore, the main elements and operation method of the device 100according to one or more embodiments of the present disclosure aredescribed. The device 100 of the present disclosure may be implementedin various forms. For example, the device 100 disclosed herein may be amobile device such as a smart phone, a tablet PC, a personal digitalassistants (PDA), a portable multimedia player (PMP), and an MP3 player,or a stationary device such as a smart TV, and a desktop computer.

According to a recent trend of convergence in digital devices, a greatvariety of mobile devices or their equivalences may be used as thedevice 100 of the present disclosure. Furthermore, any device that cancommunicate between devices and transmit or receive information to orfrom the communication control server 400 via the communication network300 may be used as the device 100 of the present disclosure.

Hereinafter, main elements and an operation method of the communicationcontrol server 400 according to one or more embodiments of the presentdisclosure will be described.

FIG. 4 is an exemplary block diagram illustrating main elements of acommunication control server shown in FIG. 1 according to one or moreembodiments.

Referring to FIGS. 1 and 4 , the communication control server 400according to one or more embodiments of the present disclosure may beconfigured to include a server communication unit 410, a server controlunit 420, and a server storage unit 430.

The server communication unit 410 supports a function of transmitting orreceiving information to or from the one or more devices 100 through thecommunication network 300. For example, the server communication unit410 of the present disclosure may receive a D2D communication requestfrom any one of the devices 100 and transmit a response message to thedevice 100.

The server control unit 420 performs the whole control of thecommunication control server 400 according to one or more embodiments ofthe present disclosure.

Particularly, the server control unit 420 according to one or moreembodiments of the present disclosure may receive a D2D communicationrequest for content, including a neighboring device list and informationabout an available communication interface, from one of the devices 100through the server communication unit 410. At this time, the servercontrol unit 420 may further receive a content possession list, which isa list of possessed contents, from the device 100 through the servercommunication unit 410.

Thereafter, in case of directly managing information about deviceshaving contents, the server control unit 420 may check information aboutany other device having content in the neighboring device list receivedfrom the device 100, extract the other device as a content providingdevice, and provide this information to the device 100. If there are twoor more content providing devices, the server control unit 420 may checkinformation about a communication interface received from the device 100and information about a communication interface as to each of otherdevices having contents, then extract one of the content providingdevices or arrange the content providing devices on the basis ofpriority for the communication interface, and provide relatedinformation to the device 100.

On the other hand, if the device management server 500 managesinformation about devices which participate in D2D communication, theserver control unit 420 may check information about other devices havingcontents through interworking with the device management server 500. Forthis, the server control unit 420 may perform a process of deliveringinformation about the content requested by the device 100 to the devicemanagement server 500 or delivering a content possession list receivedfrom the device 100 to the device management server 500 and therebysupporting the device management server 500 that manages informationabout devices participating in D2D communication and information aboutcontents possessed by respective devices.

Additionally, information about a communication interface of the device100 may be varied in real time. The device 100 that participates in D2Dcommunication may provide information about an available communicationinterface to the communication control server 400. Then, by consideringthis information, the communication control server 400 may change acontent providing device in real time or notify this to the device 100and thereby support the device 100 that uses content.

The server storage unit 430 stores all programs according to theexecution of functions of the communication control server 400. Inparticular, the server storage unit 430 according to the presentdisclosure may store and manage information about devices 100 whichparticipate in D2D communication. At this time, the server storage unit430 may store information about content possessed by each of the devices100 and about a communication interface available in the device, and thelike.

The server storage unit 430 of the present disclosure may be a storagearea located in the communication control server 400, or a data storageserver which is located at the outside of the communication controlserver 400 and capable of data transmission/reception with thecommunication control server 400.

Hereinbefore, the main element and operation method of the communicationcontrol server 400 according to one or more embodiments of the presentdisclosure are described.

Hereinbefore, the communication control server 400 according to one ormore embodiments of the present disclosure is described.

In view of hardware, the communication control server 400 according toone or more embodiments of the present disclosure has the sameconfiguration as a typical web server or network server. However, inview of software, the communication control server 400 includes aprogram module implemented by means of computer languages such as C,C++, Java, Visual Basic, Visual C, and the like.

Additionally, the web server or network server refers to a computersystem, or computer software (web server program) installed therefor,which is connected with many unspecified clients and/or other serversthrough an open-type computer network such as Internet, receives a taskrequest from such a client or other web server, and provides a taskresult. However, the web server or network server should be understoodas a broader concept including a series of application programs runningthereon as well as the above-mentioned web server program and furtherincluding, in a certain case, various kinds of database constructedtherein. The communication control server 400 may be implemented usingvarious web server programs offered depending on the OS such as DOS,Windows, Linux, UNIX, Macintosh, etc. in hardware for a typical server.Representatively, website or IIS (Internet Information Server) used inthe Windows environment and CERN, NCSA, APPACH, etc. used in the UNIXenvironment may be used.

Additionally, the communication control server 400 of the presentdisclosure may be implemented as one or more servers that operate in aserver-based computing manner or cloud manner. Particularly, informationtransmitted or received through the system of the present disclosure maybe offered through a cloud computing function which may be storedpermanently in a cloud computing device on Internet.

Meanwhile, the memory or storage unit equipped in the device 100 and thecommunication control server 400 stores information therein. In oneembodiment, the memory or storage unit is a computer-readable medium.The memory or storage unit may be a volatile memory unit in oneembodiment and may be a nonvolatile memory unit in another embodiment.In various embodiments, the memory or storage unit may include, forexample, a hard disk device, an optical disk device, or any otherhigh-volume storage device.

In addition, the term “module” used herein may refer to a component ordevice which is formed of software, hardware, or combination thereof,and performs certain tasks. The module may include, for example,components, such as software components, object-oriented softwarecomponents, class components and task components, processes, functions,attributes, procedures, subroutines, segments of program code, drivers,data, databases, data structures, tables, arrays, and variables. Thefunctionality provided for in the components and modules may be combinedinto fewer components and modules or further separated into additionalcomponents and modules.

Although this description and drawings illustrate exemplary deviceelements, the subject matters and functional operations disclosed hereinmay be implemented by different type digital electronic circuits orimplemented by computer software, firmware or hardware including astructure disclosed herein and structural equivalent thereof, or anycombination thereof. The subject matters disclosed herein may beimplemented by at least one computer program product, namely at leastone module regarding computer program commands encoded on a programstorage medium so as to control the operation of a device according tothe present disclosure or allow execution thereby. A computer-readablemedium may be a machine-readable storage device, a machine-readablestorage board, a memory device, a machine-readable composition ofmaterial affecting wave-type signaling, or a combination thereof.

Hereinafter, a D2D content providing method according to one or moreembodiments of the present disclosure will be described.

FIG. 5 is an exemplary flow diagram illustrating a D2D content providingmethod performed at a device according to one or more embodiments.

Referring to FIGS. 1 and 5 , the device 100 of the present disclosurediscovers a neighboring device (S101) which is connectible according asa module for supporting D2D communication, namely, the first interface111 shown in FIG. 3 , is activated. Herein, the first interface 111 maybe activated by a user's request or through access to a specific service(e.g., access to an application) that supports D2D communication of thepresent disclosure.

Then the device 100 creates a neighboring device list as to thediscovered neighboring devices (S103).

Thereafter, the device 100 transmits a D2D communication request forspecific content, including the neighboring device list, to thecommunication control server 400 (S105). At this time, the D2Dcommunication request may further include information about an availablecommunication interface.

Thereafter, the device 100 may receive, from the communication controlserver 400, information about a content providing device selected fromamong neighboring devices contained in the neighboring device list,based on the information about the communication interface (S107).

For example, if the second and third devices 100 b and 100 c arecontained as neighboring devices in the neighboring device list createdby the first device 100 a, the first device 100 a may transmit thecreated neighboring device list together with the information about theavailable communication interface to the communication control server400. Then the communication control server 400 checks information aboutthe second and third devices 100 b and 100 c and identifies a devicehaving the same content as content requested by the first device 100 a.If only the second device 100 b has the content requested by the firstdevice 100 a, the communication control server 400 may designate thesecond device 100 b as a content providing device and then offerinformation about the second device 100 b to the first device 100 a. Onthe other hand, if both the second and third devices 100 b and 100 chave the content requested by the first device 100 a, the communicationcontrol server 400 may check the information about communicationinterfaces of the second and third devices 100 b and 100 c and thenselect a device having the same communication interface as that of thefirst device 100 a.

The device 100 that identifies the content providing device selectedfrom among neighboring devices by the communication control server 400through this process may request and receive content from the identifiedcontent providing device (S109).

In addition, at the step S105, the device 100 may further transmit acontent possession list, which is a list of possessed contents, to thecommunication control server 400.

Hereinafter, the D2D content providing method according to embodimentsof the present disclosure will be described in more detail.

FIG. 6 is an exemplary flow diagram illustrating a D2D content providingmethod according to one or more embodiments, and FIG. 7 is an exemplaryflow diagram illustrating a D2D content providing method according toone or more embodiments.

Before description with reference to FIGS. 6 and 7 , for convenience ofexplanation, let's suppose that the device 100 is a user's device whichrequests content, namely, requests D2D communication, and theneighboring device 100 n is other user's device which neighbors near thedevice 100. The plural neighboring devices 100 n may exist and therespective neighboring devices 100 n may or may not have contentrequested by the device 100.

Additionally, the communication control server 400 of the presentdisclosure may store and manage information about all devices thatparticipate in D2D communication. In this case, the information aboutall devices participating in D2D communication may be managed by thedevice management server 500, and the communication control server 400may check a device list stored in the device management server 500,extract a content providing device by using this list, and providerelated information to the device 100 that requests the D2Dcommunication.

Referring to FIG. 6 first, a case where the communication control server400 stores and manages the information about all devices participatingin the D2D communication will be described.

In FIG. 6 , the device 100 discovers one or more neighboring deviceslocated within a specific range (S201). Also, the device 100 creates aneighboring device list that contains one or more neighboring devices(S203), and transmits a D2D communication request for specific content,including the created neighboring device list, to the communicationcontrol server 400 (S205).

The communication control server 400 that receives the request primarilychecks information about other devices having the content requested bythe device 100 (S207).

Thereafter, the communication control server 400 extracts a contentproviding device and transmits related information to the device 100. Inthis case, if there are two or more content providing devices, thecommunication control server 400 may compare information about acommunication interface of the device 100 with information about acommunication interface of each device contained in the device listtransmitted from the device management server 500 and then extract thefinal content providing device (S211).

Additionally, the communication control server 400 is in a state wherethe device 100 requests specific content, and since the device 100 maybe designated as a content providing device for another device, maystore information about content requested by the device 100 andinformation about a communication interface in response toidentification information of the device 100.

Then the communication control server 400 transmits information aboutthe content providing device to the device 100 (S211), and the device100 receiving the information requests content from the contentproviding device (S213) and receives the requested content from theneighboring device 100 n (S215).

The content providing device of the present disclosure one of aplurality of neighboring devices adjacent to the device 100 and refersto a device designated by the communication control server 400 in viewof information about a communication interface.

Additionally, if there are two or more content providing devices, thedevice 100 may request content from such content providing devices andperform a process of merging received fragmentary files of content.

The communication control server 400 of the present disclosure mayidentify the content providing device through interworking with thedevice management server 500 that manages a list of devices whichparticipate in the D2D communication.

This will be described with reference to FIG. 7 .

Referring to FIG. 7 , the device 100 discovers neighboring deviceslocated within a specific range (S301), and creates a neighboring devicelist that contains identification information about the discoveredneighboring devices (S303).

Thereafter, the device 100 transmits a request message to the devicemanagement server 500 in order to participate in D2D communication byobtaining a list of one or more other devices storing all or part ofdesired content, namely, information about a content providing device(S305). The D2D request message of the present disclosure contains atransaction ID (TID) for identifying a transaction, source addressinformation for indicating an address of a message-sending device, anddestination address information for indicating an address of amessage-receiving device, and may further contain an identifier, name,size, etc. of desired content.

The destination address information of the present disclosure refers toan address of a message-receiving device, i.e., an address of the devicemanagement server 500. The device 100 may obtain information about thedevice management server 500 by accessing a designated service for D2Dcommunication, and transmit the request message to the device managementserver 500 by using the obtained information. At this time, the device100 may transmit the request message to the device management server 500through a UDP tracker protocol (UDPT).

The communication control server 400 monitors and detects the requestmessage transmitted by the device 100 (S307). At this time, thecommunication control server 400 may forward the message, transmittedthrough the communication network 300, to itself by shinkhole routing,or copy and detect the message in a mirroring manner.

The communication control server 400 monitors and detects the requestmessage transmitted by the device 100 in order to provide informationabout a content providing device to the device 100. If this process isnot performed, the device 100 may merely receive, from the devicemanagement server 500, information about a device having the samecontent as requested, and may not receive information about a contentproviding device selected from among neighboring devices.

For this, the communication control server 400 of the present disclosuremonitors, detects and collects the request message delivered to thedevice management server 500 by the device 100 (S307), and then changesa transaction ID contained in the request message (S309). The changedtransaction ID in the present disclosure only needs to be different fromthe transaction ID contained in the request message and does not need tobe set to a specific transaction ID. Thereafter, the communicationcontrol server 400 transmits the request message with the changedtransaction ID to the device management server 500 and requests a devicelist (S311).

The device management server 500 transmits the device list to the device100 in response to the request received at step S305 (S313). At thistime, the device list contains the transaction ID changed by thecommunication control server 400. Also, the device management server 500registers the device 100 as a device which participates in D2Dcommunication (S317).

On the other hand, the device 100 that receives the device list from thedevice management server 500 at the step S313 compares the transactionID contained in the transmitted request message. Then, since thecomparison result indicates disagreement, the device 100 ignores thedevice list received through the step S313 (S315).

In this process, the communication control server 400 changes the sourceaddress information contained in the request message collected at thestep S307 to its own IP (S319).

Then, the communication control server 400 may transmit a device listrequest message with the changed source address information to thedevice management server 500 and receive a device list (S321˜S323).Since the source address information contained in the device listrequest message received from the communication control server 400 ischanged to the communication control server 400, the device managementserver 500 may transmit the device list to the communication controlserver 400.

At this time, the communication control server 400 may provide thedevice management server 500 with the neighboring device list receivedfrom the device 100 and information about content requested by thedevice 100, and then may receive the device list containing onlyinformation about a device having the content among neighboring devicescontained in the neighboring device list.

In addition, the communication control server 400 may provide the devicemanagement server 500 with information about content requested by thedevice 100, and then may receive the device list containing informationabout a device having the content.

Also, the device management server 500 may register the communicationcontrol server 400 as one device that participates in D2D communication(S325).

Thereafter, the communication control server 400 may extract the finalcontent providing device by changing the priority of a device accordingto information about a communication interface in the received devicelist or deleting or adding a specific device (S327). At this time, thecommunication control server 400 may arrange devices in the order ofpriorities according to the information about the communicationinterface and then create a list of the content providing devices.

Then, the communication control server 400 transmits information aboutthe content providing devices to the device 100 (S329). Therefore, thedevice 100 may request and receive content from the correspondingcontent providing devices according to the information about the contentproviding devices (S331˜S333).

At this time, the device 100 may receive in parallel one or morefragmentary files of the requested content from one or more contentproviding devices and, by merging the received fragmentary files,complete a content file desired to be received.

Additionally, at the step S305, the device 100 may further transmit acontent possession list which is a list of contents possessed by thedevice 100. The device management server 500 that receives the contentpossession list may store the content possession list together withinformation about content requested by the device 100 at the step 317 ofregistering information about the device 100 and thereby manageinformation about devices which participate in D2D communication.

Hereinbefore, the D2D content providing method according to embodimentsof the present disclosure is described.

The above-discussed D2D content providing method of the presentdisclosure may be provided in the form of a computer-readable mediumsuitable for storing computer program instructions and data. The D2Dcontent providing method according to one or more embodiments of thepresent disclosure may be performed by the device, including steps ofcreating a neighboring device list by discovering at least oneconnectible neighboring device, transmitting a D2D communication requestfor content to a communication control server, the request including theneighboring device list and information about an available communicationinterface, receiving, from the communication control server, informationabout one or more content providing devices selected from amongneighboring devices contained in the neighboring device list, based onthe information about the communication interface, and requesting andreceiving content from the content providing device.

In this case, a program recorded on the recording medium may perform theabove-described functions by being read, installed and executed in thecomputer.

In order to allow the computer to read the program recorded on therecording medium and to execute the functions implemented by theprogram, the above-described program may include codes encoded incomputer languages such as C, C++, JAVA, and machine language which canbe read through a device interface of the computer by a processor (CPU)of the computer.

This code may include a function code related to a function or the likethat defines the above-described functions, and may include an executionprocedure-related control code necessary for the processor of thecomputer to execute the above-described functions in accordance with apredetermined procedure. Also, such a code may further include a memoryreference related code as to which additional information or mediarequired for the processor of the computer to execute theabove-described functions should be referenced at any location (address)of the internal or external memory of the computer. In addition, whenthe processor of the computer needs to communicate with any othercomputer, server, etc., which are at remote locations, to perform theabove-described functions, the code may further include acommunication-related code as to how to communicate with which remotecomputer, server, etc., what information or media should be transmittedor received during communication, and the like.

This computer-readable medium, e.g., a recording medium, suitable forstoring computer program instructions and data includes magnetic mediasuch as a hard disk, a floppy disk, and a magnetic tape, optical mediasuch as a compact disc read only memory (CD-ROM) and a digital versatiledisc (DVD), magneto-optical media such as a floptical disk, andsemiconductor memories such as a read only memory (ROM), a random accessmemory (RAM), a flash memory, an erasable programmable ROM (EPROM), andan electrically EPROM (EEPROM). A processor and memory may besupplemented by or integrated with specific-purpose logical circuit.

Further, the computer-readable recording medium may be distributed overnetworked computer systems so that computer-readable code can be storedand executed in a distributed fashion. In addition, functional programsand their associated code and code segments for implementing the presentdisclosure may be easily deduced or altered by programmers of thetechnical field of the present disclosure in consideration of the systemenvironment of a computer that reads a recording medium and executes theprogram.

While the present disclosure contains many specific implementationdetails, these should not be construed as limitations on the scope ofthe disclosure or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particulardisclosure. Certain features that are described in the presentdisclosure in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable subcombination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a subcombination or variation of a subcombination.

Although operations are illustrated as being performed in apredetermined order in the drawings, it should not be construed that theoperations are required to be performed sequentially or in thepredetermined order, which is illustrated to obtain a preferable result,or that all of the illustrated operations are required to be performed.In some cases, multi-tasking and parallel processing may beadvantageous. Also, it should not be construed that the division ofvarious system components are required in all types of implementation.It should be understood that the described program components andsystems are generally integrated as a single software product orpackaged into a multiple-software product.

What is claimed is:
 1. A device-to-device (D2D) content providing methodat a device, the method comprising: creating, at the device, aneighboring device list by discovering one or more neighboring devicesconnectible to the device, wherein the device includes a first interfacefor supporting D2D communication and a second interface for supportingaccess to a communication network, and wherein the second interfaceincludes at least one communication module; transmitting, at the device,to a communication control server, a D2D communication request includingthe neighboring device list, information about a type of the at leastone communication module of the second interface of the device, andinformation about a specific content, wherein the D2D communicationrequest is electrical signals to request the communication controlserver to select at least one content-providing device from among theone or more neighboring devices indicated in the neighboring devicelist; receiving, at the device, from the communication control server,information about the selected at least one content-providing device,wherein from among the one or more neighboring devices indicated in theneighboring device list, the communication control server selects the atleast one content-providing device having a same content as the specificcontent requested by the device, based on the information about thespecific content, and further having a same type of at least onecommunication module as the type of the at least one communicationmodule of the second interface of the device, based on the informationabout the type of the at least one communication module of the secondinterface of the device; requesting, at the device, the selected atleast one content-providing device to provide the specific content; andreceiving, at the device, the specific content from the selected atleast one content-providing device, wherein the method includes, whenthe one or more neighboring devices to be connectible to the device arenot discovered in the neighboring device list of the one or moreneighboring devices: transmitting the D2D communication requestincluding only the information about an available type of at least onecommunication interface module of each of the one or more neighboringdevices to the communication control server; receiving, from thecommunication control server, the information about at least oneavailable device to provide the specific content selected based on theinformation about the type of at least one communication interfacemodule; requesting the at least one available device for providing thespecific content in response to the information about the at least oneavailable device; and receiving the specific content from the at leastone available device.
 2. The method of claim 1, wherein said creatingthe neighboring dev ice list of the one or more neighboring devicesincludes: obtaining identification information about at least one otherdevice through a D2D discovery message transmitted and received within aspecific range, obtaining the identification information about the atleast one other device by emitting the D2D discovery message within thespecific range and then receiving a corresponding response message, orobtaining the identification information about the at least one otherdevice through interworking with a digital unit (DU) connected with oneor more radio units (RUs) located in an access network accessed by thedevice, and creating the neighboring device list of one or moreneighboring devices by defining the obtained identification informationabout the other device as a neighboring device.
 3. The method of claim1, wherein said creating the neighboring dev ice list of one or moreneighboring devices comprises: discovering connectible one or more otherdevices; calculating a content transmission quality factor between thediscovered one or more other devices; and selecting other device, amongthe discovered one or more other devices, having the calculated contenttransmission quality factor greater than a given value, and thencreating the ne ighboring device list of one or more neighboring devicesby defining the selected other device, among the discovered one or moreother devices, as the neighboring device.
 4. The method of claim 1,wherein the information about the type of the at least one communicationinterface module includes communication interface information about atleast one of Wi-Fi, Bluetooth, LTE (Long Term Evolution), and 3Gcommunication which are available at the device.
 5. The method of claim1, further comprising: when the at least one available device exists twoor more available devices, merging contents each received from the twoor more available devices.
 6. The method of claim 1, wherein thetransmitting further comprises: transmitting a content possession list,which is a list of one or more contents possessed by the device, to thecommunication control server.
 7. A device-to-device (D2D) contentproviding method at a communication control server communicating with adevice including a first interface for supporting D2D communication anda second interface for supporting access to a communication network, thesecond interface including at least one communication module, the methodcomprising: receiving, from the device, a D2D communication requestincluding a neighboring device list, information about a type of the atleast one communication module of the second interface of the device,and information about a specific content, wherein the device creates theneighboring device list by discovering one or more neighboring devicesconnectible to the device, and wherein the D2D communication request iselectrical signals to request the communication control server to selectat least one content-providing device from among the one or moreneighboring devices indicated in the neighboring device list; selecting,from among the one or more neighboring devices indicated in theneighboring device list, the at least one content-providing devicehaving a same content as the specific content requested by the device,based on the information about the specific content, and further havinga same type of at least one communication module as the type of the atleast one communication interface module of the second interface of thedevice, based on the information about the type of the at least onecommunication module of the second interface of the device; andtransmitting, to the device, information about the selected at least onecontent-providing device, wherein said D2D content providing methodcomprising, when the one or more neighboring devices to be connectibleto the device are not discovered in the neighboring device list of theone or more neighboring devices: receiving, from the device, the D2Dcommunication request including only the information about an availabletype of the at least one communication interface module of each of theone or more neighboring devices; selecting, among the one or moreneighboring devices, the at least one content-pro viding device havingthe available type of the at least one communication interface module;and transmitting, to the device, the information about the at least oneavailable device to provide the specific content selected based on theinformation about the available type of the at least one communicationinterface module.